Single-membrane organoids: their types and functions

Cells of eukaryotes are characterized by a complex structure. Its main components are the plasma membrane, cytoplasm, which contains membrane organoids, inclusions, organoids without membranes and nucleus.

Membrane organoids have one or two membranes. They are permanent elements of the cell, characterized by a peculiar structure and perform corresponding functions.

Cellular nucleus, mitochondria, as well as plastids (chloro-, chromo- and leucoplasts) belong to the dvembrane structures of the cell. Non-membrane elements are ribosomes and a cell center.

During the cell cycle, the cytoskeleton elements may change. So, for example, during the process of division in the cell cytoplasmic ducts disappear, a new structure appears - the spindle of division.

Single-membrane organoids: let us dwell on their characteristics.

These structures are constituent elements of eukaryotic cells, which are separated from the cytosol by a single membrane. Single-membrane organelles of the cell include the endoplasmic reticulum, the Golgi apparatus and the derived structures from it-the lysosome.

The endoplasmic reticulum is a closed system of tubules that permeate the entire cytosol. It divides the cell into separate parts and is responsible for the transport of substances. The endoplasmic reticulum was discovered in 1945 using an electron microscope, which allowed us to see a particularly loose structure throughout the cytoplasm.

Endoplasmic reticulum is granular and agranular. A smooth (agranular) endoplasmic reticulum is responsible for the synthesis of lipids and polysaccharides, and the granular contains on its surface the ribosomes in which proteins are formed. This structure facilitates the transfer of various compounds throughout the cell, circulating the nutrients.

It should be noted that the granular reticulum cisterns bind to the core shell and take part in the formation of new nuclear envelopes that are formed after cell division.

The Golgi apparatus can be of various shapes, but in most cases it has the appearance of thickened disks that form a diktiosome. Ductiosis leaves the tubes, at the end of which are concentrated vesicles. The Golgi apparatus accumulates substances that are synthesized in the cell and taken out of it. This organelle is well developed in glandular cells.

Its vesicles are involved in the formation of the cytoplasmic membrane, as well as individual organoids - primary lysosomes.

Lysosomes are membrane structures of rounded form, containing enzymes, through which the cell is able to break down various organic substances. These single-membrane organelles perform another function - they break down certain structural elements of cells without affecting its functioning, providing an additional source of nutrition with insufficient nutrient intake. In addition, lysosomes are responsible for the destruction of dead and unnecessary organelles.

It should be noted that all single-membrane organoids are important for maintaining cellular homeostasis, since they ensure the normal functioning of cells.